Spring mounted removable scissors for looms

ABSTRACT

A weft yarn cutting assembly including linearly moveable drive means, cam means, scissor means have at least one moveable member for cooperation with the cam means and means connecting the drive means and the scissor means, the connecting means being yieldable in the direction normal to the direction of movement of the drive means.

United States Patent [1 1 Flamand Mar. 4, 1975 1 1 SPRING MOUNTED REMOVABLE S CISSORS FOR LOOMS [75] Inventor: Maurice R. Flamand, Cumberland,

[73] Assignee: Rockwell International Corporation,

Pittsburgh, Pa.

221 Filed: Nov. 14, 1973 21 Appl.No.:407,009

[52] U.S. C1. 139/302 [51] Int. Cl D03d 49/70 [58] Field of Search 139/122, 125, 126, 263,

[56] References Cited UNITED STATES PATENTS 9/1960 Whewell 139/263 12/1961 Pfarrwaller 139/126 4/1963 Pfarrwaller et a1. 139/302 Primary Examiner-Henry S. Jaudon [57] ABSTRACT A weft yarn cutting assembly including linearly moveable drive means, cam means, scissor means have at least one moveable member for cooperation with the cam means and means connecting the drive means and the scissor means, the connecting means being yieldable in the direction normal to the direction of movement of the drive means.

3 Claims, 4 Drawing Figures SPRING MOUNTED REMOVABLE SCISSORS FOR LOOMS BACKGROUND OF THE INVENTION In textile looms of the type where the weft or filling year is inserted into a warp shed from a stationary source located externally of the shed, it is possible to have either one or two unfinished selvages. Whether one or both selvages are unfinished depends upon the exact method by which insertion of the weft is accomplished. In either case, a finished selvage can be accomplished by tucking the loose weft end back into the next following warp shed and locking it in position when the loom harnesses are reversed. Alternatively, the selvage is often left unfinished and cutters used to remove excess quantities of the free weft end. Normally the weft ends are removed by means of scissors which are operated in timed sequence with the reed beat up. The scissors are commonly operated by suitable mechanical connections with a driving cam that is synchronized with operation of the loom reed and harness motions.

Obviously after protracted periods of operation, the scissors will become dulled and no longer function efficiently to cut the free weft ends. When this occurs, it is necessary for a trained mechanic to disassemble the scissors mounting and driving mechanism and replace dulled scissors. This operation, of necessity, results in costly loom downtime and further requires that new or sharpened scissors be again mounted in a way that their operation is timed to operate at the proper moment when a weft end is present.

It is a principal object of this invention to provide an improved weft yarn cutting assembly which can be readily changed without requiring skilled workers.

An additional object of this invention is to provide a readily changeable weft yarn cutting assembly which includes a resilient connecting means that permits scissors elements to be readily changed on the loom.

Other objects and advantages of this invention will be in part obvious and in part explained by reference to the accompanying specification and drawings in which:

DESCRIPTION OF THE DRAWINGS FIG. I is a side elevation, partly fragmentary, showing the yarn cutting assembly of this invention;

FIG. 2 is a side elevation of the camming plate used to operate the scissors mechanism, with part broken away;

FIG. 3 is a top elevation of the cutting assembly shown in FIG. 1; and

FIG. 4 is a front perspective showing the manner in which the scissors means can be moved between an inner operating position and on outer position where it can be removed.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings for a more detailed explanation of the weft cutting assembly of this invention, and particularly to FIG. 1, there is shown the weft cutting assembly indicated generally by numeral 10. The cutting assembly comprises a drive means 11 which is mounted for reciprocating movement in a substantially rectilinear path. Drive means 11 is shown as having a series of teeth 12 on one end which mate with an appropriate gear member 13 that is operably connected to a source of motive power. The particular means by which drive means 11 is connected to its source of power is not relevant to the present invention and therefore need not be described in detail, as any appropriate connection means can be used.

Mounted on the loom is a cam means 15 (see FIG. 2) that, in the modification shown, contains a pair of cam tracks 16. Cam means 15 can be secured to the loom structure by suitable means such as bolts (not shown) that pass through the openings indicated by numeral 17 in FIG. 2. Mounted within the cam tracks 16 are a pair of scissor blades 18 and 19 which together define scissor means for effecting cutting of the free ends of the weft yarns. Each of the blades 18 and 19 pivots about the pivot axis 20 and each blade also has a cam roller 21 which rides in the cam slots 16.

This weft cutting assembly further comprises means for connecting drive means 11 to the scissors means made up of blades 18 and 19. This connecting means comprises a resilient member 25 which is connected at one end to drive means 11 by means of a threaded fastener indicated by numeral 26. At the other end of connector 25, there is a small rectangular plate 27 that is secured to the connecting means 25 by means of rivets 28. Here again types of fasteners other than rivets could be used. At the upper end of plate 27 is a small stub shaft 29 that defines the axis 20 of scissor rotation. This shaft is received into the opening 30, shown as provided through the cutting blades 18 and 19 in FIG. 4. The connecting element 25 is substantially unyielding in the direction parallel to the direction of movement of drive means 11 but is yieldable in the direction normal to the direction of travel of drive means 11. The connecting means 25 is in this case constructed in the form of a spring which has substantially greater width than thickness. By utilizing this geometry, it is possible for means 25 to be moved from the phantom position 35 shown in FIG. 4 to the solid position indicated by numeral 36.

In operation, the drive means 11 is reciprocated in a substantially rectilinear path by the means of the gear member 13. This reciprocating movement causes the scissor means to also reciprocate due to the fact that connecting means 25 is substantially unyielding in the direction corresponding to the width of means 25. Reciprocal movement of means25 causes similar reciprocation of blades 18 and 19 (and the rest of the scissors assembly) through their connection with stub shaft 29. As the cutting means is reciprocated, the roller cams 2!. must follow the cam tracks 16 and this causes rotation of the blades 18 and 19 to perform their severing operation.

From the preceding description of the construction, it can be seen readily that to replace worn cutter blades 18 and 19 it is necessary only to move the connecting element 25 from position 35 to position 36. In the outer position (36) the blades will have moved so that the cam rollers 21 are free from the mounting blade and the blades can then be slid from stub shaft 29. Replacement with a new set of blades occurs by the reverse procedure of sliding a new set of blades onto stub shaft 29 and then returning element 25 to position 35 so that rollers 21 are again within slot 16. Such changing of the cutting element can be effected at any vertical location of the scissors and requires no skilled operator to effect such replacement. It should be mentioned that the configuration shown and described includes two moveable cutting blades 18 and 19 but it is possible to utilize a stationary blade together with one moveable blade.

Although the present invention has been described in connection with preferred embodiments, it is to be understood that modifications and variations may be resorted to without departing from the spirit and scope of the invention, as those skilled in the art will readily understand. Such modifications and variations are considered to be within the purview and scope of the invention and the appended claims.

I claim:

1. A weft cutting assembly for use on a shuttleless loom where weft yarn is drawn for a stationary source, said assembly comprising drive means connected to a source of motive power for reciprocating substantially rectilinear movement, cam means mounted on the 4 loom, scissor means including at least one movable member mounted for operative cooperation with said cam means, and means connecting said drive means to said scissor means, said connecting means including spring-like member of substantially greater width than thickness which is attached at one end to said drive means and at the other end to said scissor means.

2. A weft cutting mechanism as defined in claim 1 wherein the moveable member of said scissor means includes a cam follower for contact with the said cam means. v

3. A weft cutting mechanism as defined in claim 1 wherein said scissor means comprises two moveable members. 

1. A weft cutting assembly fOr use on a shuttleless loom where weft yarn is drawn for a stationary source, said assembly comprising drive means connected to a source of motive power for reciprocating substantially rectilinear movement, cam means mounted on the loom, scissor means including at least one movable member mounted for operative cooperation with said cam means, and means connecting said drive means to said scissor means, said connecting means including spring-like member of substantially greater width than thickness which is attached at one end to said drive means and at the other end to said scissor means.
 2. A weft cutting mechanism as defined in claim 1 wherein the moveable member of said scissor means includes a cam follower for contact with the said cam means.
 3. A weft cutting mechanism as defined in claim 1 wherein said scissor means comprises two moveable members. 